EVALUATION OF A REMOTE SENSING BASED METHOD FOR THE ASSESSMENT OF AGRICULTURAL CROP RESIDUES ON THE SOIL SURFACE

Abstract

Increased agricultural mechanization in the recent past and susceptibility of certain soils to degradation generate widespread concern among experts on the overall environmental sustainability of some of the current agricultural practices in Europe. A number of solutions could be adopted to better preserve soil resources, some of which are already supported by the Common Agricultural Policy (CAP). Researchers demonstrated that erosion and reduction in soil organic matter are among the most acute degradation issues in Europe and that the release of crop residues on the soil surface after harvesting can greatly reduce their incidence. The use of a permanent soil cover (e.g. by use of crop residues) is one of the three fundamental principles of Conservation Agriculture. Quantifying the amount of crop residues on the ground is important for soil and water protection, modelling of erosion processes and legislation enforcement purposes. However, common monitoring methods based on ground sampling are expensive and likely to be impracticable on vast surfaces. Remote sensing can offer a valid alternative for monitoring. The present research intends to contribute to the efforts towards the establishments of methods for the assessment and monitoring, through remote sensing, of the effects of conservation agriculture practices on the environment, with focus on soil resources. In this respect, the research specific objective is the evaluation of a remote sensing based method for the quantification of crop residue cover in a conservation agriculture farm in Northern Italy by use of hyperspectral satellite imagery. Results achieved show that not only crop residues percent cover is linearly related to certain remote sensing-based indices, therefore making possible to estimate how well soil is preserved from weathering, but also that spaceborne hyperspectral sensors such as Hyperion appear to have great potentiality towards monitoring of other environmental targets due to their very high spectral and spatial resolution. The research was deeply inspired by the outcomes of a European project (“Sustainable Agriculture and Soil Conservation through simplified cultivation techniques” - SoCo) aimed at improving protection of soil resources in the European agriculture sector through a stock taking and promotion of soil-friendly agriculture practices and systems, in particular simplified cultivation techniques, within the current legislative framework.